Prevalence of anatomic variations of the CoW in relation to MR imaging—detected parenchymal abnormalities in a group of 29 infants (26 term-born and 3 preterm infants imaged at term)
| Parenchymal Abnormalities | Complete CoW | Fetal-Type Origin of PCA | PcomA Absence/Hypo | AcomA Absence/Hypo | P1 Absence/Hypo | A1 Absence/Hypo |
|---|---|---|---|---|---|---|
| Abnormal signal intensity in basal ganglia (n = 17) | 4 | 6 | 7 | 4 | 2 | 1 |
| Infarction (n = 10) | 2 | 4 | 3 | 2 | 3 | 0 |
| Loss of grey/white matter differentiation (n = 3) | 0 | 2 | 2 | 1 | 1 | 0 |
| Hemorrhage (n = 2) | 1 | 0 | 1 | 0 | 0 | 0 |
| Periventricular cysts (n = 2) | 1 | 0 | 1 | 0 | 0 | 0 |
| Porencephalic cysts (n = 1) | 1 | 0 | 0 | 0 | 0 | 0 |
Note:—Hypo indicates hypoplasia.